The present invention relates to structural skylights such as acrylic or other types of plastic sheet skylights which have curved panes or panels forming to an underlying support frame of structural aluminum, for example. More particularly, the present invention relates to a vaulted skylight constructed of modular panels wherein spaced apart inner and outer sheets of each modular panel are peripherally connected to isolate an air space therebetween yet allow relative movement between the inner and outer sheets when the sheets are simultaneously cold formed into an arc during placement upon the underlying structural support frame. Further, the present invention relates to a composite skylight construction of light-transmitting panels and underlying support structure which is quickly field-assembled without the use of a plurality of individual fasteners and the attending manual labor.
Vaulted skylights are constructed of a composite that, for example, includes panes of acrylic supported by a structural frame of aluminum. The panes and frame can form various curved cross-sectional shapes, e.g., half round vaults, quarter round vaults, and barrel vaults. These curved shapes are typically defined by the rigid structural frame of pre-shaped structural aluminum tubing. Translucent or transparent panels of acrylic may cover the tubing frame to form a roof or watertight enclosure which admits sunlight. The acrylic sheets are normally cold formed to the tubing frame during installation and are held in place using clamps or straps. The structural tubing frame can be supported by a curb rail which rests upon an underlying foundation such as a brick wall, concrete curb, timber frame, or the like.
Vaulted structural skylights often feature two or more parallel plastic panels which are separated by a small distance (e.g., 1/2"-1") to provide an insulating airspace therebetween. For an enclosure covered by the skylight, which uses a heating or air-conditioning system, the double panes contribute to energy conservation. Skylights using two or more spaced, parallel plastic sheets require field assembly of a first sheet layer and thereafter the addition of the second sheet layer. Such field assembly typically employs a large number of closely spaced apart fasteners such as sheet metal screws, rivets or the like which must be manually installed. An installer must climb upon the aluminum support frame after each panel is properly positioned and fasten the screws or rivets one at a time. This piecemeal field assembly of multiple pane or sheet layers creates a number of problems. The assembly of two individual sheets is a complicated and expensive installation. The facing inner surfaces of the two panels are often subjected to damage by scratching, for example. Dust, pollen, and other airborn debris can accumulate on the inner surfaces of the layers when the sheet layers are assembled separately (on site) upon the supporting structural frame.
Some attempts have been made to eliminate the use of a multitude of fasteners such as sheets metal screws and/or rivets. For example, the Jansen U.S. Pat. No. 3,762,120 provides a skylight device wherein two filling panels or partitions are provided. However, this patent describes a sequential installation of the underlying or lower panel followed by the on-site installation of the second panel. The Jansen patent suffers from the aforedescribed problems of dust accumulation, complicated on-site installation and the danger of damage to inside surfaces of the panels.
Other prior art devices contemplate the use of preformed or preshaped panels which are either factory assembled or field assembled. Such panels are typically preformed prior to assembly on-site. This type of construction causes problems in that the pre-formed or precurved skylight panels are not easily and economically transportable to the job site because of excessive space requirements.